Gas propellant devices such as gas engines and gas burners include a gas cartridge loading mechanism provided on a loading portion of the body of the gas propellant device for loading a gas cartridge. The gas cartridge loading mechanism has a collar retainer provided on a cartridge accommodating portion, and a positioning lever provided on the collar retainer for assisting visual alignment by the user between a connecting collar of the gas cartridge and the positioning lever so that the gas cartridge can be loaded while keeping correct orientation relative to the collar retainer. More particularly, the connecting collar of the gas cartridge has a notch, which is used for alignment relative to the positioning lever in order to ensure proper loading of the gas cartridge in the cartridge accommodating portion of the gas propellant device.
With the gas cartridge loading mechanism thus constructed, when the gas cartridge is to be loaded on the gas propellant device, the gas cartridge is first placed on the cartridge accommodating portion of the gas propellant device. In this instance, the collar notch of the gas cartridge is disposed relatively far distant from the positioning lever provided on the collar retainer. The collar notch is then brought into alignment with the positioning lever through visual observation by the user and, while keeping the collar notch and the positioning lever in the thus aligned condition, a set lever is operated to displace the gas cartridge toward the collar retainer until the collar of the gas cartridge is retained by the collar retainer. The gas cartridge is thus loaded on the gas propellant device.
One example of such gas cartridge loading mechanisms is disclosed in Japanese Patent No. 2705619 corresponding to JP 08-247467A published on Sep. 27, 1996.
The disclosed gas cartridge loading mechanism is not fully satisfactory in that when the gas cartridge is set in the cartridge accommodating portion, the collar notch of the gas cartridge is disposed relatively far distant from the positioning lever. Furthermore, the positioning lever is disposed inside the cartridge accommodating portion and hence is uneasy to observe from the outside of the gas propellant device. Due to the foregoing difficulties, a visual alignment work made by the user for aligning the collar notch relative to the positioning lever is rendered tedious and time-consuming. Thus the conventional gas cartridge loading mechanism is relatively uneasy to use.